<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package    CodeIgniter
 * @author    EllisLab Dev Team
 * @copyright    Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
 * @copyright    Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
 * @license    http://opensource.org/licenses/MIT	MIT License
 * @link    https://codeigniter.com
 * @since    Version 3.0.0
 * @filesource
 */
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * PDO SQLite Database Adapter Class
 *
 * Note: _DB is an extender class that the app controller
 * creates dynamically based on whether the query builder
 * class is being used or not.
 *
 * @package        CodeIgniter
 * @subpackage    Drivers
 * @category    Database
 * @author        EllisLab Dev Team
 * @link        https://codeigniter.com/user_guide/database/
 */
class CI_DB_pdo_sqlite_driver extends CI_DB_pdo_driver
{

    /**
     * Sub-driver
     *
     * @var    string
     */
    public $subdriver = 'sqlite';

    // --------------------------------------------------------------------

    /**
     * ORDER BY random keyword
     *
     * @var    array
     */
    protected $_random_keyword = ' RANDOM()';

    // --------------------------------------------------------------------

    /**
     * Class constructor
     *
     * Builds the DSN if not already set.
     *
     * @param    array $params
     * @return    void
     */
    public function __construct($params)
    {
        parent::__construct($params);

        if (empty($this->dsn)) {
            $this->dsn = 'sqlite:';

            if (empty($this->database) && empty($this->hostname)) {
                $this->database = ':memory:';
            }

            $this->database = empty($this->database) ? $this->hostname : $this->database;
        }
    }

    // --------------------------------------------------------------------

    /**
     * Show table query
     *
     * Generates a platform-specific query string so that the table names can be fetched
     *
     * @param    bool $prefix_limit
     * @return    string
     */
    protected function _list_tables($prefix_limit = FALSE)
    {
        $sql = 'SELECT "NAME" FROM "SQLITE_MASTER" WHERE "TYPE" = \'table\'';

        if ($prefix_limit === TRUE && $this->dbprefix !== '') {
            return $sql . ' AND "NAME" LIKE \'' . $this->escape_like_str($this->dbprefix) . "%' "
            . sprintf($this->_like_escape_str, $this->_like_escape_chr);
        }

        return $sql;
    }

    // --------------------------------------------------------------------

    /**
     * Fetch Field Names
     *
     * @param    string $table Table name
     * @return    array
     */
    public function list_fields($table)
    {
        // Is there a cached result?
        if (isset($this->data_cache['field_names'][$table])) {
            return $this->data_cache['field_names'][$table];
        }

        if (($result = $this->query('PRAGMA TABLE_INFO(' . $this->protect_identifiers($table, TRUE, NULL, FALSE) . ')')) === FALSE) {
            return FALSE;
        }

        $this->data_cache['field_names'][$table] = array();
        foreach ($result->result_array() as $row) {
            $this->data_cache['field_names'][$table][] = $row['name'];
        }

        return $this->data_cache['field_names'][$table];
    }

    // --------------------------------------------------------------------

    /**
     * Returns an object with field data
     *
     * @param    string $table
     * @return    array
     */
    public function field_data($table)
    {
        if (($query = $this->query('PRAGMA TABLE_INFO(' . $this->protect_identifiers($table, TRUE, NULL, FALSE) . ')')) === FALSE) {
            return FALSE;
        }

        $query = $query->result_array();
        if (empty($query)) {
            return FALSE;
        }

        $retval = array();
        for ($i = 0, $c = count($query); $i < $c; $i++) {
            $retval[$i] = new stdClass();
            $retval[$i]->name = $query[$i]['name'];
            $retval[$i]->type = $query[$i]['type'];
            $retval[$i]->max_length = NULL;
            $retval[$i]->default = $query[$i]['dflt_value'];
            $retval[$i]->primary_key = isset($query[$i]['pk']) ? (int)$query[$i]['pk'] : 0;
        }

        return $retval;
    }

    // --------------------------------------------------------------------

    /**
     * Replace statement
     *
     * @param    string $table Table name
     * @param    array $keys INSERT keys
     * @param    array $values INSERT values
     * @return    string
     */
    protected function _replace($table, $keys, $values)
    {
        return 'INSERT OR ' . parent::_replace($table, $keys, $values);
    }

    // --------------------------------------------------------------------

    /**
     * Truncate statement
     *
     * Generates a platform-specific truncate string from the supplied data
     *
     * If the database does not support the TRUNCATE statement,
     * then this method maps to 'DELETE FROM table'
     *
     * @param    string $table
     * @return    string
     */
    protected function _truncate($table)
    {
        return 'DELETE FROM ' . $table;
    }

}
